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freebsd-skq/sys/geom/geom_subr.c
jh 70139e5fa6 Fix deadlock between GEOM class unloading and withering. Withering can't 
proceed while g_unload_class() blocks the event thread. Fix this by not
running g_unload_class() as a GEOM event and dropping the topology lock
when withering needs to proceed.

PR:		kern/139847
Silence on:	freebsd-geom
2010-05-05 18:53:24 +00:00

1347 lines
33 KiB
C
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/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/devicestat.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/errno.h>
#include <sys/sbuf.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
#include <machine/stdarg.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
#ifdef KDB
#include <sys/kdb.h>
#endif
struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
struct g_hh00 {
struct g_class *mp;
int error;
int post;
};
/*
* This event offers a new class a chance to taste all preexisting providers.
*/
static void
g_load_class(void *arg, int flag)
{
struct g_hh00 *hh;
struct g_class *mp2, *mp;
struct g_geom *gp;
struct g_provider *pp;
g_topology_assert();
if (flag == EV_CANCEL) /* XXX: can't happen ? */
return;
if (g_shutdown)
return;
hh = arg;
mp = hh->mp;
hh->error = 0;
if (hh->post) {
g_free(hh);
hh = NULL;
}
g_trace(G_T_TOPOLOGY, "g_load_class(%s)", mp->name);
KASSERT(mp->name != NULL && *mp->name != '\0',
("GEOM class has no name"));
LIST_FOREACH(mp2, &g_classes, class) {
if (mp2 == mp) {
printf("The GEOM class %s is already loaded.\n",
mp2->name);
if (hh != NULL)
hh->error = EEXIST;
return;
} else if (strcmp(mp2->name, mp->name) == 0) {
printf("A GEOM class %s is already loaded.\n",
mp2->name);
if (hh != NULL)
hh->error = EEXIST;
return;
}
}
LIST_INIT(&mp->geom);
LIST_INSERT_HEAD(&g_classes, mp, class);
if (mp->init != NULL)
mp->init(mp);
if (mp->taste == NULL)
return;
LIST_FOREACH(mp2, &g_classes, class) {
if (mp == mp2)
continue;
LIST_FOREACH(gp, &mp2->geom, geom) {
LIST_FOREACH(pp, &gp->provider, provider) {
mp->taste(mp, pp, 0);
g_topology_assert();
}
}
}
}
static int
g_unload_class(struct g_class *mp)
{
struct g_geom *gp;
struct g_provider *pp;
struct g_consumer *cp;
int error;
g_topology_lock();
g_trace(G_T_TOPOLOGY, "g_unload_class(%s)", mp->name);
retry:
G_VALID_CLASS(mp);
LIST_FOREACH(gp, &mp->geom, geom) {
/* We refuse to unload if anything is open */
LIST_FOREACH(pp, &gp->provider, provider)
if (pp->acr || pp->acw || pp->ace) {
g_topology_unlock();
return (EBUSY);
}
LIST_FOREACH(cp, &gp->consumer, consumer)
if (cp->acr || cp->acw || cp->ace) {
g_topology_unlock();
return (EBUSY);
}
/* If the geom is withering, wait for it to finish. */
if (gp->flags & G_GEOM_WITHER) {
g_topology_sleep(mp, 1);
goto retry;
}
}
/*
* We allow unloading if we have no geoms, or a class
* method we can use to get rid of them.
*/
if (!LIST_EMPTY(&mp->geom) && mp->destroy_geom == NULL) {
g_topology_unlock();
return (EOPNOTSUPP);
}
/* Bar new entries */
mp->taste = NULL;
mp->config = NULL;
LIST_FOREACH(gp, &mp->geom, geom) {
error = mp->destroy_geom(NULL, mp, gp);
if (error != 0) {
g_topology_unlock();
return (error);
}
}
/* Wait for withering to finish. */
for (;;) {
gp = LIST_FIRST(&mp->geom);
if (gp == NULL)
break;
KASSERT(gp->flags & G_GEOM_WITHER,
("Non-withering geom in class %s", mp->name));
g_topology_sleep(mp, 1);
}
G_VALID_CLASS(mp);
if (mp->fini != NULL)
mp->fini(mp);
LIST_REMOVE(mp, class);
g_topology_unlock();
return (0);
}
int
g_modevent(module_t mod, int type, void *data)
{
struct g_hh00 *hh;
int error;
static int g_ignition;
struct g_class *mp;
mp = data;
if (mp->version != G_VERSION) {
printf("GEOM class %s has Wrong version %x\n",
mp->name, mp->version);
return (EINVAL);
}
if (!g_ignition) {
g_ignition++;
g_init();
}
error = EOPNOTSUPP;
switch (type) {
case MOD_LOAD:
g_trace(G_T_TOPOLOGY, "g_modevent(%s, LOAD)", mp->name);
hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
hh->mp = mp;
/*
* Once the system is not cold, MOD_LOAD calls will be
* from the userland and the g_event thread will be able
* to acknowledge their completion.
*/
if (cold) {
hh->post = 1;
error = g_post_event(g_load_class, hh, M_WAITOK, NULL);
} else {
error = g_waitfor_event(g_load_class, hh, M_WAITOK,
NULL);
if (error == 0)
error = hh->error;
g_free(hh);
}
break;
case MOD_UNLOAD:
g_trace(G_T_TOPOLOGY, "g_modevent(%s, UNLOAD)", mp->name);
DROP_GIANT();
error = g_unload_class(mp);
PICKUP_GIANT();
if (error == 0) {
KASSERT(LIST_EMPTY(&mp->geom),
("Unloaded class (%s) still has geom", mp->name));
}
break;
}
return (error);
}
static void
g_retaste_event(void *arg, int flag)
{
struct g_class *cp, *mp;
struct g_geom *gp, *gp2;
struct g_hh00 *hh;
struct g_provider *pp;
g_topology_assert();
if (flag == EV_CANCEL) /* XXX: can't happen ? */
return;
if (g_shutdown)
return;
hh = arg;
mp = hh->mp;
hh->error = 0;
if (hh->post) {
g_free(hh);
hh = NULL;
}
g_trace(G_T_TOPOLOGY, "g_retaste(%s)", mp->name);
LIST_FOREACH(cp, &g_classes, class) {
LIST_FOREACH(gp, &cp->geom, geom) {
LIST_FOREACH(pp, &gp->provider, provider) {
if (pp->acr || pp->acw || pp->ace)
continue;
LIST_FOREACH(gp2, &mp->geom, geom) {
if (!strcmp(pp->name, gp2->name))
break;
}
if (gp2 != NULL)
g_wither_geom(gp2, ENXIO);
mp->taste(mp, pp, 0);
g_topology_assert();
}
}
}
}
int
g_retaste(struct g_class *mp)
{
struct g_hh00 *hh;
int error;
if (mp->taste == NULL)
return (EINVAL);
hh = g_malloc(sizeof *hh, M_WAITOK | M_ZERO);
hh->mp = mp;
if (cold) {
hh->post = 1;
error = g_post_event(g_retaste_event, hh, M_WAITOK, NULL);
} else {
error = g_waitfor_event(g_retaste_event, hh, M_WAITOK, NULL);
if (error == 0)
error = hh->error;
g_free(hh);
}
return (error);
}
struct g_geom *
g_new_geomf(struct g_class *mp, const char *fmt, ...)
{
struct g_geom *gp;
va_list ap;
struct sbuf *sb;
g_topology_assert();
G_VALID_CLASS(mp);
sb = sbuf_new_auto();
va_start(ap, fmt);
sbuf_vprintf(sb, fmt, ap);
va_end(ap);
sbuf_finish(sb);
gp = g_malloc(sizeof *gp, M_WAITOK | M_ZERO);
gp->name = g_malloc(sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
gp->class = mp;
gp->rank = 1;
LIST_INIT(&gp->consumer);
LIST_INIT(&gp->provider);
LIST_INSERT_HEAD(&mp->geom, gp, geom);
TAILQ_INSERT_HEAD(&geoms, gp, geoms);
strcpy(gp->name, sbuf_data(sb));
sbuf_delete(sb);
/* Fill in defaults from class */
gp->start = mp->start;
gp->spoiled = mp->spoiled;
gp->dumpconf = mp->dumpconf;
gp->access = mp->access;
gp->orphan = mp->orphan;
gp->ioctl = mp->ioctl;
return (gp);
}
void
g_destroy_geom(struct g_geom *gp)
{
g_topology_assert();
G_VALID_GEOM(gp);
g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
KASSERT(LIST_EMPTY(&gp->consumer),
("g_destroy_geom(%s) with consumer(s) [%p]",
gp->name, LIST_FIRST(&gp->consumer)));
KASSERT(LIST_EMPTY(&gp->provider),
("g_destroy_geom(%s) with provider(s) [%p]",
gp->name, LIST_FIRST(&gp->provider)));
g_cancel_event(gp);
LIST_REMOVE(gp, geom);
TAILQ_REMOVE(&geoms, gp, geoms);
g_free(gp->name);
g_free(gp);
}
/*
* This function is called (repeatedly) until the geom has withered away.
*/
void
g_wither_geom(struct g_geom *gp, int error)
{
struct g_provider *pp;
g_topology_assert();
G_VALID_GEOM(gp);
g_trace(G_T_TOPOLOGY, "g_wither_geom(%p(%s))", gp, gp->name);
if (!(gp->flags & G_GEOM_WITHER)) {
gp->flags |= G_GEOM_WITHER;
LIST_FOREACH(pp, &gp->provider, provider)
if (!(pp->flags & G_PF_ORPHAN))
g_orphan_provider(pp, error);
}
g_do_wither();
}
/*
* Convenience function to destroy a particular provider.
*/
void
g_wither_provider(struct g_provider *pp, int error)
{
pp->flags |= G_PF_WITHER;
if (!(pp->flags & G_PF_ORPHAN))
g_orphan_provider(pp, error);
}
/*
* This function is called (repeatedly) until the has withered away.
*/
void
g_wither_geom_close(struct g_geom *gp, int error)
{
struct g_consumer *cp;
g_topology_assert();
G_VALID_GEOM(gp);
g_trace(G_T_TOPOLOGY, "g_wither_geom_close(%p(%s))", gp, gp->name);
LIST_FOREACH(cp, &gp->consumer, consumer)
if (cp->acr || cp->acw || cp->ace)
g_access(cp, -cp->acr, -cp->acw, -cp->ace);
g_wither_geom(gp, error);
}
/*
* This function is called (repeatedly) until we cant wash away more
* withered bits at present. Return value contains two bits. Bit 0
* set means "withering stuff we can't wash now", bit 1 means "call
* me again, there may be stuff I didn't get the first time around.
*/
int
g_wither_washer()
{
struct g_class *mp;
struct g_geom *gp, *gp2;
struct g_provider *pp, *pp2;
struct g_consumer *cp, *cp2;
int result;
result = 0;
g_topology_assert();
LIST_FOREACH(mp, &g_classes, class) {
LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
if (!(pp->flags & G_PF_WITHER))
continue;
if (LIST_EMPTY(&pp->consumers))
g_destroy_provider(pp);
else
result |= 1;
}
if (!(gp->flags & G_GEOM_WITHER))
continue;
LIST_FOREACH_SAFE(pp, &gp->provider, provider, pp2) {
if (LIST_EMPTY(&pp->consumers))
g_destroy_provider(pp);
else
result |= 1;
}
LIST_FOREACH_SAFE(cp, &gp->consumer, consumer, cp2) {
if (cp->acr || cp->acw || cp->ace) {
result |= 1;
continue;
}
if (cp->provider != NULL)
g_detach(cp);
g_destroy_consumer(cp);
result |= 2;
}
if (LIST_EMPTY(&gp->provider) &&
LIST_EMPTY(&gp->consumer))
g_destroy_geom(gp);
else
result |= 1;
}
}
return (result);
}
struct g_consumer *
g_new_consumer(struct g_geom *gp)
{
struct g_consumer *cp;
g_topology_assert();
G_VALID_GEOM(gp);
KASSERT(!(gp->flags & G_GEOM_WITHER),
("g_new_consumer on WITHERing geom(%s) (class %s)",
gp->name, gp->class->name));
KASSERT(gp->orphan != NULL,
("g_new_consumer on geom(%s) (class %s) without orphan",
gp->name, gp->class->name));
cp = g_malloc(sizeof *cp, M_WAITOK | M_ZERO);
cp->geom = gp;
cp->stat = devstat_new_entry(cp, -1, 0, DEVSTAT_ALL_SUPPORTED,
DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
return(cp);
}
void
g_destroy_consumer(struct g_consumer *cp)
{
struct g_geom *gp;
g_topology_assert();
G_VALID_CONSUMER(cp);
g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
g_cancel_event(cp);
gp = cp->geom;
LIST_REMOVE(cp, consumer);
devstat_remove_entry(cp->stat);
g_free(cp);
if (gp->flags & G_GEOM_WITHER)
g_do_wither();
}
static void
g_new_provider_event(void *arg, int flag)
{
struct g_class *mp;
struct g_provider *pp;
struct g_consumer *cp;
g_topology_assert();
if (flag == EV_CANCEL)
return;
if (g_shutdown)
return;
pp = arg;
G_VALID_PROVIDER(pp);
KASSERT(!(pp->flags & G_PF_WITHER),
("g_new_provider_event but withered"));
LIST_FOREACH(mp, &g_classes, class) {
if (mp->taste == NULL)
continue;
LIST_FOREACH(cp, &pp->consumers, consumers)
if (cp->geom->class == mp)
break;
if (cp != NULL)
continue;
mp->taste(mp, pp, 0);
g_topology_assert();
}
}
struct g_provider *
g_new_providerf(struct g_geom *gp, const char *fmt, ...)
{
struct g_provider *pp;
struct sbuf *sb;
va_list ap;
g_topology_assert();
G_VALID_GEOM(gp);
KASSERT(gp->access != NULL,
("new provider on geom(%s) without ->access (class %s)",
gp->name, gp->class->name));
KASSERT(gp->start != NULL,
("new provider on geom(%s) without ->start (class %s)",
gp->name, gp->class->name));
KASSERT(!(gp->flags & G_GEOM_WITHER),
("new provider on WITHERing geom(%s) (class %s)",
gp->name, gp->class->name));
sb = sbuf_new_auto();
va_start(ap, fmt);
sbuf_vprintf(sb, fmt, ap);
va_end(ap);
sbuf_finish(sb);
pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_WAITOK | M_ZERO);
pp->name = (char *)(pp + 1);
strcpy(pp->name, sbuf_data(sb));
sbuf_delete(sb);
LIST_INIT(&pp->consumers);
pp->error = ENXIO;
pp->geom = gp;
pp->stat = devstat_new_entry(pp, -1, 0, DEVSTAT_ALL_SUPPORTED,
DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
LIST_INSERT_HEAD(&gp->provider, pp, provider);
g_post_event(g_new_provider_event, pp, M_WAITOK, pp, gp, NULL);
return (pp);
}
void
g_error_provider(struct g_provider *pp, int error)
{
/* G_VALID_PROVIDER(pp); We may not have g_topology */
pp->error = error;
}
struct g_provider *
g_provider_by_name(char const *arg)
{
struct g_class *cp;
struct g_geom *gp;
struct g_provider *pp;
LIST_FOREACH(cp, &g_classes, class) {
LIST_FOREACH(gp, &cp->geom, geom) {
LIST_FOREACH(pp, &gp->provider, provider) {
if (!strcmp(arg, pp->name))
return (pp);
}
}
}
return (NULL);
}
void
g_destroy_provider(struct g_provider *pp)
{
struct g_geom *gp;
g_topology_assert();
G_VALID_PROVIDER(pp);
KASSERT(LIST_EMPTY(&pp->consumers),
("g_destroy_provider but attached"));
KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
KASSERT (pp->ace == 0, ("g_destroy_provider with ace"));
g_cancel_event(pp);
LIST_REMOVE(pp, provider);
gp = pp->geom;
devstat_remove_entry(pp->stat);
g_free(pp);
if ((gp->flags & G_GEOM_WITHER))
g_do_wither();
}
/*
* We keep the "geoms" list sorted by topological order (== increasing
* numerical rank) at all times.
* When an attach is done, the attaching geoms rank is invalidated
* and it is moved to the tail of the list.
* All geoms later in the sequence has their ranks reevaluated in
* sequence. If we cannot assign rank to a geom because it's
* prerequisites do not have rank, we move that element to the tail
* of the sequence with invalid rank as well.
* At some point we encounter our original geom and if we stil fail
* to assign it a rank, there must be a loop and we fail back to
* g_attach() which detach again and calls redo_rank again
* to fix up the damage.
* It would be much simpler code wise to do it recursively, but we
* can't risk that on the kernel stack.
*/
static int
redo_rank(struct g_geom *gp)
{
struct g_consumer *cp;
struct g_geom *gp1, *gp2;
int n, m;
g_topology_assert();
G_VALID_GEOM(gp);
/* Invalidate this geoms rank and move it to the tail */
gp1 = TAILQ_NEXT(gp, geoms);
if (gp1 != NULL) {
gp->rank = 0;
TAILQ_REMOVE(&geoms, gp, geoms);
TAILQ_INSERT_TAIL(&geoms, gp, geoms);
} else {
gp1 = gp;
}
/* re-rank the rest of the sequence */
for (; gp1 != NULL; gp1 = gp2) {
gp1->rank = 0;
m = 1;
LIST_FOREACH(cp, &gp1->consumer, consumer) {
if (cp->provider == NULL)
continue;
n = cp->provider->geom->rank;
if (n == 0) {
m = 0;
break;
} else if (n >= m)
m = n + 1;
}
gp1->rank = m;
gp2 = TAILQ_NEXT(gp1, geoms);
/* got a rank, moving on */
if (m != 0)
continue;
/* no rank to original geom means loop */
if (gp == gp1)
return (ELOOP);
/* no rank, put it at the end move on */
TAILQ_REMOVE(&geoms, gp1, geoms);
TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
}
return (0);
}
int
g_attach(struct g_consumer *cp, struct g_provider *pp)
{
int error;
g_topology_assert();
G_VALID_CONSUMER(cp);
G_VALID_PROVIDER(pp);
g_trace(G_T_TOPOLOGY, "g_attach(%p, %p)", cp, pp);
KASSERT(cp->provider == NULL, ("attach but attached"));
cp->provider = pp;
LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
error = redo_rank(cp->geom);
if (error) {
LIST_REMOVE(cp, consumers);
cp->provider = NULL;
redo_rank(cp->geom);
}
return (error);
}
void
g_detach(struct g_consumer *cp)
{
struct g_provider *pp;
g_topology_assert();
G_VALID_CONSUMER(cp);
g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
KASSERT(cp->provider != NULL, ("detach but not attached"));
KASSERT(cp->acr == 0, ("detach but nonzero acr"));
KASSERT(cp->acw == 0, ("detach but nonzero acw"));
KASSERT(cp->ace == 0, ("detach but nonzero ace"));
KASSERT(cp->nstart == cp->nend,
("detach with active requests"));
pp = cp->provider;
LIST_REMOVE(cp, consumers);
cp->provider = NULL;
if (pp->geom->flags & G_GEOM_WITHER)
g_do_wither();
else if (pp->flags & G_PF_WITHER)
g_do_wither();
redo_rank(cp->geom);
}
/*
* g_access()
*
* Access-check with delta values. The question asked is "can provider
* "cp" change the access counters by the relative amounts dc[rwe] ?"
*/
int
g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
{
struct g_provider *pp;
int pr,pw,pe;
int error;
g_topology_assert();
G_VALID_CONSUMER(cp);
pp = cp->provider;
KASSERT(pp != NULL, ("access but not attached"));
G_VALID_PROVIDER(pp);
g_trace(G_T_ACCESS, "g_access(%p(%s), %d, %d, %d)",
cp, pp->name, dcr, dcw, dce);
KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
KASSERT(dcr != 0 || dcw != 0 || dce != 0, ("NOP access request"));
KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
/*
* If our class cares about being spoiled, and we have been, we
* are probably just ahead of the event telling us that. Fail
* now rather than having to unravel this later.
*/
if (cp->geom->spoiled != NULL && cp->spoiled &&
(dcr > 0 || dcw > 0 || dce > 0))
return (ENXIO);
/*
* Figure out what counts the provider would have had, if this
* consumer had (r0w0e0) at this time.
*/
pr = pp->acr - cp->acr;
pw = pp->acw - cp->acw;
pe = pp->ace - cp->ace;
g_trace(G_T_ACCESS,
"open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
dcr, dcw, dce,
cp->acr, cp->acw, cp->ace,
pp->acr, pp->acw, pp->ace,
pp, pp->name);
/* If foot-shooting is enabled, any open on rank#1 is OK */
if ((g_debugflags & 16) && pp->geom->rank == 1)
;
/* If we try exclusive but already write: fail */
else if (dce > 0 && pw > 0)
return (EPERM);
/* If we try write but already exclusive: fail */
else if (dcw > 0 && pe > 0)
return (EPERM);
/* If we try to open more but provider is error'ed: fail */
else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
return (pp->error);
/* Ok then... */
error = pp->geom->access(pp, dcr, dcw, dce);
KASSERT(dcr > 0 || dcw > 0 || dce > 0 || error == 0,
("Geom provider %s::%s failed closing ->access()",
pp->geom->class->name, pp->name));
if (!error) {
/*
* If we open first write, spoil any partner consumers.
* If we close last write and provider is not errored,
* trigger re-taste.
*/
if (pp->acw == 0 && dcw != 0)
g_spoil(pp, cp);
else if (pp->acw != 0 && pp->acw == -dcw && pp->error == 0 &&
!(pp->geom->flags & G_GEOM_WITHER))
g_post_event(g_new_provider_event, pp, M_WAITOK,
pp, NULL);
pp->acr += dcr;
pp->acw += dcw;
pp->ace += dce;
cp->acr += dcr;
cp->acw += dcw;
cp->ace += dce;
if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
KASSERT(pp->sectorsize > 0,
("Provider %s lacks sectorsize", pp->name));
}
return (error);
}
int
g_handleattr_int(struct bio *bp, const char *attribute, int val)
{
return (g_handleattr(bp, attribute, &val, sizeof val));
}
int
g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
{
return (g_handleattr(bp, attribute, &val, sizeof val));
}
int
g_handleattr_str(struct bio *bp, const char *attribute, const char *str)
{
return (g_handleattr(bp, attribute, str, 0));
}
int
g_handleattr(struct bio *bp, const char *attribute, const void *val, int len)
{
int error = 0;
if (strcmp(bp->bio_attribute, attribute))
return (0);
if (len == 0) {
bzero(bp->bio_data, bp->bio_length);
if (strlcpy(bp->bio_data, val, bp->bio_length) >=
bp->bio_length) {
printf("%s: %s bio_length %jd len %zu -> EFAULT\n",
__func__, bp->bio_to->name,
(intmax_t)bp->bio_length, strlen(val));
error = EFAULT;
}
} else if (bp->bio_length == len) {
bcopy(val, bp->bio_data, len);
} else {
printf("%s: %s bio_length %jd len %d -> EFAULT\n", __func__,
bp->bio_to->name, (intmax_t)bp->bio_length, len);
error = EFAULT;
}
if (error == 0)
bp->bio_completed = bp->bio_length;
g_io_deliver(bp, error);
return (1);
}
int
g_std_access(struct g_provider *pp,
int dr __unused, int dw __unused, int de __unused)
{
g_topology_assert();
G_VALID_PROVIDER(pp);
return (0);
}
void
g_std_done(struct bio *bp)
{
struct bio *bp2;
bp2 = bp->bio_parent;
if (bp2->bio_error == 0)
bp2->bio_error = bp->bio_error;
bp2->bio_completed += bp->bio_completed;
g_destroy_bio(bp);
bp2->bio_inbed++;
if (bp2->bio_children == bp2->bio_inbed)
g_io_deliver(bp2, bp2->bio_error);
}
/* XXX: maybe this is only g_slice_spoiled */
void
g_std_spoiled(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_provider *pp;
g_topology_assert();
G_VALID_CONSUMER(cp);
g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
g_detach(cp);
gp = cp->geom;
LIST_FOREACH(pp, &gp->provider, provider)
g_orphan_provider(pp, ENXIO);
g_destroy_consumer(cp);
if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
g_destroy_geom(gp);
else
gp->flags |= G_GEOM_WITHER;
}
/*
* Spoiling happens when a provider is opened for writing, but consumers
* which are configured by in-band data are attached (slicers for instance).
* Since the write might potentially change the in-band data, such consumers
* need to re-evaluate their existence after the writing session closes.
* We do this by (offering to) tear them down when the open for write happens
* in return for a re-taste when it closes again.
* Together with the fact that such consumers grab an 'e' bit whenever they
* are open, regardless of mode, this ends up DTRT.
*/
static void
g_spoil_event(void *arg, int flag)
{
struct g_provider *pp;
struct g_consumer *cp, *cp2;
g_topology_assert();
if (flag == EV_CANCEL)
return;
pp = arg;
G_VALID_PROVIDER(pp);
for (cp = LIST_FIRST(&pp->consumers); cp != NULL; cp = cp2) {
cp2 = LIST_NEXT(cp, consumers);
if (!cp->spoiled)
continue;
cp->spoiled = 0;
if (cp->geom->spoiled == NULL)
continue;
cp->geom->spoiled(cp);
g_topology_assert();
}
}
void
g_spoil(struct g_provider *pp, struct g_consumer *cp)
{
struct g_consumer *cp2;
g_topology_assert();
G_VALID_PROVIDER(pp);
G_VALID_CONSUMER(cp);
LIST_FOREACH(cp2, &pp->consumers, consumers) {
if (cp2 == cp)
continue;
/*
KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
*/
KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
cp2->spoiled++;
}
g_post_event(g_spoil_event, pp, M_WAITOK, pp, NULL);
}
int
g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
{
int error, i;
i = len;
error = g_io_getattr(attr, cp, &i, var);
if (error)
return (error);
if (i != len)
return (EINVAL);
return (0);
}
#if defined(DIAGNOSTIC) || defined(DDB)
/*
* This function walks the mesh and returns a non-zero integer if it
* finds the argument pointer is an object. The return value indicates
* which type of object it is believed to be. If topology is not locked,
* this function is potentially dangerous, but we don't assert that the
* topology lock is held when called from debugger.
*/
int
g_valid_obj(void const *ptr)
{
struct g_class *mp;
struct g_geom *gp;
struct g_consumer *cp;
struct g_provider *pp;
#ifdef KDB
if (kdb_active == 0)
#endif
g_topology_assert();
LIST_FOREACH(mp, &g_classes, class) {
if (ptr == mp)
return (1);
LIST_FOREACH(gp, &mp->geom, geom) {
if (ptr == gp)
return (2);
LIST_FOREACH(cp, &gp->consumer, consumer)
if (ptr == cp)
return (3);
LIST_FOREACH(pp, &gp->provider, provider)
if (ptr == pp)
return (4);
}
}
return(0);
}
#endif
#ifdef DDB
#define gprintf(...) do { \
db_printf("%*s", indent, ""); \
db_printf(__VA_ARGS__); \
} while (0)
#define gprintln(...) do { \
gprintf(__VA_ARGS__); \
db_printf("\n"); \
} while (0)
#define ADDFLAG(obj, flag, sflag) do { \
if ((obj)->flags & (flag)) { \
if (comma) \
strlcat(str, ",", size); \
strlcat(str, (sflag), size); \
comma = 1; \
} \
} while (0)
static char *
provider_flags_to_string(struct g_provider *pp, char *str, size_t size)
{
int comma = 0;
bzero(str, size);
if (pp->flags == 0) {
strlcpy(str, "NONE", size);
return (str);
}
ADDFLAG(pp, G_PF_CANDELETE, "G_PF_CANDELETE");
ADDFLAG(pp, G_PF_WITHER, "G_PF_WITHER");
ADDFLAG(pp, G_PF_ORPHAN, "G_PF_ORPHAN");
return (str);
}
static char *
geom_flags_to_string(struct g_geom *gp, char *str, size_t size)
{
int comma = 0;
bzero(str, size);
if (gp->flags == 0) {
strlcpy(str, "NONE", size);
return (str);
}
ADDFLAG(gp, G_GEOM_WITHER, "G_GEOM_WITHER");
return (str);
}
static void
db_show_geom_consumer(int indent, struct g_consumer *cp)
{
if (indent == 0) {
gprintln("consumer: %p", cp);
gprintln(" class: %s (%p)", cp->geom->class->name,
cp->geom->class);
gprintln(" geom: %s (%p)", cp->geom->name, cp->geom);
if (cp->provider == NULL)
gprintln(" provider: none");
else {
gprintln(" provider: %s (%p)", cp->provider->name,
cp->provider);
}
gprintln(" access: r%dw%de%d", cp->acr, cp->acw, cp->ace);
gprintln(" spoiled: %d", cp->spoiled);
gprintln(" nstart: %u", cp->nstart);
gprintln(" nend: %u", cp->nend);
} else {
gprintf("consumer: %p (%s), access=r%dw%de%d", cp,
cp->provider != NULL ? cp->provider->name : "none",
cp->acr, cp->acw, cp->ace);
if (cp->spoiled)
db_printf(", spoiled=%d", cp->spoiled);
db_printf("\n");
}
}
static void
db_show_geom_provider(int indent, struct g_provider *pp)
{
struct g_consumer *cp;
char flags[64];
if (indent == 0) {
gprintln("provider: %s (%p)", pp->name, pp);
gprintln(" class: %s (%p)", pp->geom->class->name,
pp->geom->class);
gprintln(" geom: %s (%p)", pp->geom->name, pp->geom);
gprintln(" mediasize: %jd", (intmax_t)pp->mediasize);
gprintln(" sectorsize: %u", pp->sectorsize);
gprintln(" stripesize: %u", pp->stripesize);
gprintln(" stripeoffset: %u", pp->stripeoffset);
gprintln(" access: r%dw%de%d", pp->acr, pp->acw,
pp->ace);
gprintln(" flags: %s (0x%04x)",
provider_flags_to_string(pp, flags, sizeof(flags)),
pp->flags);
gprintln(" error: %d", pp->error);
gprintln(" nstart: %u", pp->nstart);
gprintln(" nend: %u", pp->nend);
if (LIST_EMPTY(&pp->consumers))
gprintln(" consumers: none");
} else {
gprintf("provider: %s (%p), access=r%dw%de%d",
pp->name, pp, pp->acr, pp->acw, pp->ace);
if (pp->flags != 0) {
db_printf(", flags=%s (0x%04x)",
provider_flags_to_string(pp, flags, sizeof(flags)),
pp->flags);
}
db_printf("\n");
}
if (!LIST_EMPTY(&pp->consumers)) {
LIST_FOREACH(cp, &pp->consumers, consumers) {
db_show_geom_consumer(indent + 2, cp);
if (db_pager_quit)
break;
}
}
}
static void
db_show_geom_geom(int indent, struct g_geom *gp)
{
struct g_provider *pp;
struct g_consumer *cp;
char flags[64];
if (indent == 0) {
gprintln("geom: %s (%p)", gp->name, gp);
gprintln(" class: %s (%p)", gp->class->name, gp->class);
gprintln(" flags: %s (0x%04x)",
geom_flags_to_string(gp, flags, sizeof(flags)), gp->flags);
gprintln(" rank: %d", gp->rank);
if (LIST_EMPTY(&gp->provider))
gprintln(" providers: none");
if (LIST_EMPTY(&gp->consumer))
gprintln(" consumers: none");
} else {
gprintf("geom: %s (%p), rank=%d", gp->name, gp, gp->rank);
if (gp->flags != 0) {
db_printf(", flags=%s (0x%04x)",
geom_flags_to_string(gp, flags, sizeof(flags)),
gp->flags);
}
db_printf("\n");
}
if (!LIST_EMPTY(&gp->provider)) {
LIST_FOREACH(pp, &gp->provider, provider) {
db_show_geom_provider(indent + 2, pp);
if (db_pager_quit)
break;
}
}
if (!LIST_EMPTY(&gp->consumer)) {
LIST_FOREACH(cp, &gp->consumer, consumer) {
db_show_geom_consumer(indent + 2, cp);
if (db_pager_quit)
break;
}
}
}
static void
db_show_geom_class(struct g_class *mp)
{
struct g_geom *gp;
db_printf("class: %s (%p)\n", mp->name, mp);
LIST_FOREACH(gp, &mp->geom, geom) {
db_show_geom_geom(2, gp);
if (db_pager_quit)
break;
}
}
/*
* Print the GEOM topology or the given object.
*/
DB_SHOW_COMMAND(geom, db_show_geom)
{
struct g_class *mp;
if (!have_addr) {
/* No address given, print the entire topology. */
LIST_FOREACH(mp, &g_classes, class) {
db_show_geom_class(mp);
db_printf("\n");
if (db_pager_quit)
break;
}
} else {
switch (g_valid_obj((void *)addr)) {
case 1:
db_show_geom_class((struct g_class *)addr);
break;
case 2:
db_show_geom_geom(0, (struct g_geom *)addr);
break;
case 3:
db_show_geom_consumer(0, (struct g_consumer *)addr);
break;
case 4:
db_show_geom_provider(0, (struct g_provider *)addr);
break;
default:
db_printf("Not a GEOM object.\n");
break;
}
}
}
static void
db_print_bio_cmd(struct bio *bp)
{
db_printf(" cmd: ");
switch (bp->bio_cmd) {
case BIO_READ: db_printf("BIO_READ"); break;
case BIO_WRITE: db_printf("BIO_WRITE"); break;
case BIO_DELETE: db_printf("BIO_DELETE"); break;
case BIO_GETATTR: db_printf("BIO_GETATTR"); break;
case BIO_FLUSH: db_printf("BIO_FLUSH"); break;
case BIO_CMD0: db_printf("BIO_CMD0"); break;
case BIO_CMD1: db_printf("BIO_CMD1"); break;
case BIO_CMD2: db_printf("BIO_CMD2"); break;
default: db_printf("UNKNOWN"); break;
}
db_printf("\n");
}
static void
db_print_bio_flags(struct bio *bp)
{
int comma;
comma = 0;
db_printf(" flags: ");
if (bp->bio_flags & BIO_ERROR) {
db_printf("BIO_ERROR");
comma = 1;
}
if (bp->bio_flags & BIO_DONE) {
db_printf("%sBIO_DONE", (comma ? ", " : ""));
comma = 1;
}
if (bp->bio_flags & BIO_ONQUEUE)
db_printf("%sBIO_ONQUEUE", (comma ? ", " : ""));
db_printf("\n");
}
/*
* Print useful information in a BIO
*/
DB_SHOW_COMMAND(bio, db_show_bio)
{
struct bio *bp;
if (have_addr) {
bp = (struct bio *)addr;
db_printf("BIO %p\n", bp);
db_print_bio_cmd(bp);
db_print_bio_flags(bp);
db_printf(" cflags: 0x%hhx\n", bp->bio_cflags);
db_printf(" pflags: 0x%hhx\n", bp->bio_pflags);
db_printf(" offset: %jd\n", (intmax_t)bp->bio_offset);
db_printf(" length: %jd\n", (intmax_t)bp->bio_length);
db_printf(" bcount: %ld\n", bp->bio_bcount);
db_printf(" resid: %ld\n", bp->bio_resid);
db_printf(" completed: %jd\n", (intmax_t)bp->bio_completed);
db_printf(" children: %u\n", bp->bio_children);
db_printf(" inbed: %u\n", bp->bio_inbed);
db_printf(" error: %d\n", bp->bio_error);
db_printf(" parent: %p\n", bp->bio_parent);
db_printf(" driver1: %p\n", bp->bio_driver1);
db_printf(" driver2: %p\n", bp->bio_driver2);
db_printf(" caller1: %p\n", bp->bio_caller1);
db_printf(" caller2: %p\n", bp->bio_caller2);
db_printf(" bio_from: %p\n", bp->bio_from);
db_printf(" bio_to: %p\n", bp->bio_to);
}
}
#undef gprintf
#undef gprintln
#undef ADDFLAG
#endif /* DDB */
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